He was born in Chicago, the son of Harry Alter, a pioneer in radio and television distribution, and wife Esther. He attended the University of Chicago High School before enrolling at Purdue University to study engineering.

His education was interrupted during his sophomore year when he enlisted in the U.S. Army Air Forces. Commissioned as a lieutenant in 1942, Mr. Alter would fly 31 combat missions as a navigator and bombardier in a B-24 over Nazi-occupied Europe. Shot down over Soviet-held territory, Mr. Alter and his surviving crew mates bartered the wreckage of their plane for cigarettes and safe passage back to their base in southern Italy.

Mr. Alter would refer to his war years as "an impermanent but defining chapter of his life," recounting those events and more in a charming and forthright 2006 memoir titled "From Campus to Combat: A College Boy Becomes a WWII Army Flier."

"Dad was an example of how those who have seen real combat are often the biggest advocates of peace," said his son, Jonathan, a journalist, author and television producer. "He organized businessmen to oppose the Vietnam War and was an early opponent of the Iraq War."

Newsmakers and others from the Chicago area who died in 2014.

Returning from the war, he earned a bachelor's degree from Lake Forest College and later an MBA from the U. of C. School of Business. He became president and CEO of the Harry Alter Co., the refrigeration and air conditioning wholesaler business that had been founded by his father on the South Side.

In 1952 he met and married Joanne Hammerman, and the couple started to make their marks in politics and on the local landscape. Both were young aides to Gov. Adlai Stevenson II in his 1952 and 1956 presidential campaigns, and later they both held senior roles in several Democratic campaigns in Illinois.

Their homes — a large Victorian on Hawthorne Place on the North Side and later a handsome apartment on East Lake Shore Drive — played host to all manner of movers and shakers, among them the Rev. Martin Luther King Jr., Edward Kennedy, Harold Washington, Oprah Winfrey and U.S. Sens. Paul Simon and Dick Durbin. In 2003 the couple hosted an early fundraiser for Barack Obama's 2004 Senate campaign.

In their North Side home they also raised four children, reading to them every night and allowing them to be part of any political discussion taking place.

Mr. Alter was an enthusiastic backer of his wife's political ambitions. In 1972 she became one of the first two women elected to the board of the Metropolitan Sanitary District (now the Metropolitan Water Reclamation District of Greater Chicago).

In 1975, Mr. Alter and others created Friends of the Parks, the nonprofit organization that acts as a watchdog and environmental advocate for Chicago-area parks and forest preserves. He served as president and chairman of the board for many years. (His wife, who died in 2008, had been a founding member of Friends of the Chicago River.)

"Dad was gratified by how much better the parks are but knew there was still a lot of work to be done," said his daughter, Jennifer Alter Warden.

Mr. Alter once served as chairman of the Commission on Mortgage Practices, which issued recommendations that led to the outlawing of "redlining" — the widespread denial of mortgages in poor neighborhoods.

He was a past president of the National Heating and Air Conditioning Wholesalers and the Air Conditioning and Refrigeration Wholesalers. He also was a board member of many civic groups, among them the Jewish Vocational Service, Business and Professional People for the Public Interest and the Chicago Academy of Sciences (now the Peggy Notebaert Nature Museum.)

In his later years, Mr. Alter was an adjunct professor of business at Roosevelt University, tutored in the WITS program co-founded by his wife and in his late eighties completed three years of the great books Basic Program at the U. of C.

He was never reluctant to share his opinions and his feeling about his city. In reaction to the plans to remodel Soldier Field on 2001, Mr. Alter wrote an impassioned letter that was printed in the Tribune. It read, in part:

"Where is the outrage when the Bears propose a monstrous new structure, resembling a bathtub toy, sitting on top of, and towering over, the stately old Soldier Field colonnades? ... Where is the outrage when the cost of the new stadium seats will be so high that only suburbanites and expense-account executives can afford them? Where is the outrage when the total public subsidy … could instead give Chicago 8,000 new teachers and police officers, or maybe 100 new schools and libraries?"

In addition to his son and daughter, he is survived by another son, Harrison; another daughter, Jamie Alter Lynton; a sister, Mitzy Marks; and 11 grandchildren.

A memorial service is planned for 10 a.m. Thursday in the South Gallery of the nature museum, 2430 N. Cannon Drive, Chicago.